Subject: Indian Geography

The unique physiographic features of the Western Ghats and its drainage pattern explain the absence of delta formation along India's western coast, which stands in stark contrast to the extensive deltas found along the eastern coast.

Factors Preventing Delta Formation

Physiographic Characteristics

• The Western Ghats run parallel and close to the Arabian Sea coast, leaving limited coastal plain for delta formation.
• The steep gradient and short length of rivers flowing westward result in high stream velocity, limiting sediment deposition.
• The presence of submerged coastline creates natural harbors instead of deltaic plains along the Konkan and Malabar coast.

Hydrological Factors

• The rivers originating from Western Ghats are relatively shorter with swift-flowing nature.
• The high gradient causes rivers to maintain their erosive power till they meet the Arabian Sea, preventing sediment accumulation.
• The presence of backwaters (Kayals) along the Malabar coast acts as sediment traps, further reducing delta formation potential.

Marine Conditions

• The Arabian Sea has strong currents and high tidal range which wash away the sediments brought by rivers.
• The presence of a steep continental shelf near the coast prevents the accumulation of sediments.
• The deep waters close to the shore facilitate quick dispersal of river sediments into the sea.

Sediment Characteristics

• Studies indicate that rivers like Netravati, Chaliyar, Bharathapuzha, and Periyar contribute significant sediments to the Arabian Sea.
• However, the sediment yield varies significantly between exploited and protected basins, with exploited basins contributing four times more sediment.
• The combination of marine conditions and coastal morphology prevents these sediments from forming deltas.

The absence of deltas along the western coast is a classic example of how geomorphological processes, shaped by the interaction between physiography, hydrology, and marine conditions, influence coastal landform development. This unique feature has led to the formation of distinctive coastal features like backwaters and natural harbors, which play crucial roles in the region's ecology and economy.